Grape pomace powder valorization: a novel ingredient to improve the nutritional quality of gluten-free muffins

Grape pomace powders (GPP) were obtained and used to elaborate a gluten-free premix suitable for use in culinary recipes. The grape pomace was dried at 55 and 75 °C and then the kinetics was studied, being the Midilli model that fitted accurately to the experimental drying data. The proximal analysis of both samples was performed, showing no significant differences between the variables studied, except for the content of crude fiber, which was higher in flours obtained at 75 °C. Moreover, the techno-functional properties of GPP were studied and did not present significant variation with temperature increase except to oil holding capacity (OHC). Based on the results, GPP obtained at 75 °C was used as an ingredient in premix formulations. The incorporation of GPP (15 and 25%) improved the nutritional composition of the muffins as their content increases, highlighting protein and crude fiber content. Likewise, these had a good level of acceptability by consumers. Taking into account grape pomace is a by-product discarded by wineries, it has a potential added value and is feasible to use as an ingredient for gluten-free muffins.